The NHL and players union will meet again on Monday after failing to make
any progress in their latest round of labour talks.
The NHL's Collective Bargaining Agreement (CBA) expires on 15 September, and if a new deal is not reached by then a lock-out could threaten the season scheduled to begin in October.
NHL executive vice-president and chief legal officer Bill Daly said: "We are very frustrated and concerned over where we are in this process.
"It is clear to us that union leadership has no interest in negotiating or making a deal to save the start of the season."
Ted Saskin, the players' association senior director, said: "Obviously we haven't come any closer to any solutions but we continue to work hard."
The two sides are due to meet in Montreal on 30 August for another two-day session.
If no deal is reached the NHL season could be delayed for the first time since 1994-1995.